Means for transferring high-potential electric currents as arcs.



Y B I m C. G. KOPPITZ.

MEANS FOR TRANSFERRING HIGH POTENTIAL ELECTRIC CURRENTS AS ARCS.

APPLICATION FILED SEPT- 19. 1913.

1,233,584. Patented July 17, 1917.

3:40am boz atbo'mm d UNITED STATES PA EFT GFFTCEQ CARL G. KOPPITZ, 0F WILKINSBURG, PENNSYLVANIA.

MEANS FOR TBANSFEBRING HIGH-POTENTIAL ELECTRIC CURRENTS AS ARCS Specification of Letters Patent.

Patented July 17, 1912,

Application filed September 19, 1913. Serial No. 790,?71.

filed October 10, 1912, I have described a process of and apparatus for interconverting direct and alternating currents, having a potential of from one or two thousand up to several hundred thousand volts, by synchronously transferring unidirectional lcurrents as arcs between rotating distributersconnected to the source of direct current. and fixed commutator-segments connected by spaced leads to difierentpo'rtions of a closed alternatingcurrent winding, the distributers being driven in synchronism with the alternating-current phases.

The present invention relates to means for increasing the conductivity of the air at a the arcing-points, by creating partial vacua thereat.

Referring to the accompanying drawing,- Figure 1 is a diagrammatic view of a portion of an'electric converter, illustrating, in section, a rotating terminal of spaced laminae and means for withdrawing the air therethrougli;

Fig. 2 is identical with Fig. 1, except that a twd part rotating terminal is employed;

Fig. 3 is a sectional side elevation of a modification employing a solid rotating terminal with a peripheral air-passage; Fig. 4 is an end elevation of the same; Fig] 5 is a sectional-side elevation of another modification employin a two-part rotating terminal of solid bloc s separated by insulation and surrounded by an air-passage, on the line V-V of-Fig. 7;

gig. 6 is a front elevation of the same; an I Fig. 7 is a horizontal section of the same on-the line VIIVII of Fig. 5.

' The converter illustrated. in Fig. comprises an alternating-current winding 1, from which spaced leads 2 extend inward to a circular series of fixed terminals 3. One

of the rotating terminals 4:, in arcing proximity to the fixed terminals 3, is carried by a radial arm 5, and is electrically connected by a lead 6 to a central slip-ring 7 on which bears a bruslrS, indicated as of positive polar1ty. Thisconstruction is generically that of my specified prior applications. Ac cording to the present invention, the rotatmg terminal 4 is constructed of a series of fiat metal laminae, spaced apart to provide intermediate airapassages. The arm 5 consists of a tube, the outer end of which is expanded to receive these laminae, insulated therefrom, and the inner end of which is connected by an air-tight joint to a fixed pipe 9 leading to a vacuum-pump 50. In operation, sutlicientair is pumpedthrough the passages between the laminae and pipes 5, and 9 to materially reduce the atmospheric pressure and increase the conductivity of the air-gap at; the arcing-point.

The apparatus of Fig. 2 is similar to that of Fig. 1, except that the rotating terminal consists of two sets of spaced laminae, e 4:, separated by insulation 10 and separately connected by leads 6, 6 to separate sliprlngs 7, 7 on which bear positive brushes 8, 8. This construction is employed where it is desired to interpose an interrupter in the circuit 6', as described in my applicatliiin Serial No. 791,312, filed September 23,

Figs. 3 and 1 illustrate a rotating terminal consisting of a solid rectangular block 4',

. somewhat smaller than and leaving a peripheral space between it and the expanded end of the tube 5, in which it is carried.

. Figs' 5, 6, 7 illustrate a modified construction employing a two-part rotating terminal consisting of solid blocks 4 and 4 separated by a sheet of insulation 10'. These ,blocks, each of which preferably has a removable wearing-face, are carried by and are in'electrical contact with the end or" a twopart metal elbow 11, fixed on a ring of menlation 12 on the end of hollow radial arm 5 The terminal blocks are surrounded by an insulating sleeve 13, leaving an intermediate ing proximity thereto, and means for contlnudusly' Withdrawing airfrom the vicinity of said movable terminal.

2. Means for transferring Inga-potential electric currents as arcs, comprising a set of fixed terminals, a movable terminal 1n arcing proximity thereto, a hollow arm carry- Uopiea of this patent may be obtained for five cents each, by addressing the ing proximity thereto, consisting of spaced parallel members, and means for withdrawing air from the arcing zone through the spaces adjacent to said members.

In testimony whereof I afix my signature in presence of two witnesses.

CARL G. KOPPITZ. Witnesses:

ALICE A. TRILL, F. B. JOYCE.

Commissioner of Eatenta Washington, D. 0. 

